Earnings Per Share (Schedule of Earnings per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income from continuing operations		$ 2,243.5	$ 2,028.8	$ 1,901.0
Net income (loss) from discontinued operations		12.6	70.3	(14.3)
Net Income Attributable to Air Products		$ 2,256.1	$ 2,099.1	$ 1,886.7
Weighted average common shares — Basic		222.0	221.6	221.2
Employee stock option and other award plans		0.5	0.9	1.1
Weighted average common shares — Diluted		222.5	222.5	222.3
Per Share Data
Basic EPS from continuing operations (in dollars per share)	[1]	$ 10.11	$ 9.16	$ 8.59
Basic EPS from discontinued operations (in dollars per share)	[1]	0.06	0.32	(0.06)
Basic EPS Attributable to Air Products (in dollars per share)	[1]	10.16	9.47	8.53
Diluted EPS from continuing operations (in dollars per share)	[1]	10.08	9.12	8.55
Diluted EPS from discontinued operations (in dollars per share)	[1]	0.06	0.32	(0.06)
Diluted EPS Attributable to Air Products (in dollars per share)	[1]	$ 10.14	$ 9.43	$ 8.49

[1] Earnings per share ("EPS") is calculated independently for each component and may not sum to total EPS due to rounding.